1. Field of the Invention
This invention relates generally to the generation of useful power from a vertical or inclined shaft opening, and, more specifically, relates to inducement on demand of a draft in a vertical passage by the introduction of stored, collected solar energy into the passage for the generation of electrical power, ventilation or for other purposes.
2. Description of the Prior Art
In the past, man has quested for power from time immemorial. Of late, a clear understanding has developed concerning the advantage to be gained from reasoned application of power from a vertical or inclined shaft opening or passage, for the generation of electricity and innumerable other applications. Typical electrical generation facilities of the past have utilized fuel combustion or nuclear reactions to fire boilers which produced a mass flow driving a turbine whose output was coupled to the electrical generating unit. The problems associated with such facilities were well understood, including the limited fuel resource availability, the cost of fuels, the generation of atmospheric and water borne pollution, and the threat of nuclear contamination or catastrophe. A need existed for an alternate energy source, which did not present the threats of biotic destruction, and which preferably did not even require a consumable fuel.
Relatively recently, various types of alternate energy source-driven vertical or inclined opening, passage or shaft power generators have been developed. As evidenced by U.S. Pat. No. 401,516 to J. A. Robb on Apr. 16, 1889, it was known that chimney shaft power could be produced by installing a propeller or turbine in a chimney or stack.
Various approaches were developed to induce a draft in a shaft-like column to drive a turbine. In U.S. Pat. No. 3,894,393 to Phillip R. Carlson on July 15, 1975, a method of generating power by chilling air at an upper inlet of a column with evaporation to then generate electrical power with a turbine installed in the lower end of the column is disclosed.
In U.S. Pat. No. 4,106,295 to P. J. Wood on Aug. 15, 1978, it is disclosed that a combination of an evaporation process along with a solar water heater could be utilized to induce a draft in an insulated column to drive a generator installed in the column.
In U.S. Pat. No. 4,157,014 to R. W. Clark, Jr. on June 5, 1979, it is further disclosed that solar energy can be utilized to heat a liquid working fluid on a desert floor, which working fluid can be ducted toward a higher elevation, lower pressure region of the system therein to permit a power transfer device to extract shaft power from the flow. It is also there taught that the natural temperature differential existing between the ambient surface temperature inside an underground mine and the surface temperature outside the mine can be utilized to heat a working fluid, again causing an upward transport of the fluid which can be harnessed to produce substantially vertical or inclined mine shaft power.
A problem common to each of the solar energy power conversion systems of the past was that their output was limited to periods during which solar input was available.
Notwithstanding the developments of the past, a need continued to exist for a practical system to produce shaft power, which system was non-polluting, continuously available for power output, and which did not require a consumable fuel for continued operation.